Platelet receptors for ATP and ADP

Platelet receptors for ATP and ADP

Both ATP and ADP are released from the dense platelet granules during activation. They are also released from endothelial cells and damaged red blood cells following injury to blood vessels. These extracellular signalling molecules interact with platelet P2 receptors to amplify ongoing platelet activation by both autocrine and paracrine mechanisms.

ATP and ADP bind to P2 receptors. The platelet receptors for ADP are P2Y₁ and P2Y₁₂ while those for ATP is P2X₁ ion channel. P2Y₁ is G(q)-protein-coupled receptor, while P2Y₁₂ is G(i)-protein-coupled. P2Y₁ receptor initiates platelet aggregation by mobilization of calcium stores. P2Y₁₂ receptor coupled to adenylyl cyclase inhibition is needed for full aggregation response to ADP and stabilization of aggregates [1]. Both the P2Y receptors are useful targets for antiplatelet therapy [2].

References

1. C Gachet. Identification, Characterization, and Inhibition of the Platelet ADP Receptors. Int J Hematol. 2001 Dec;74(4):375-81.
2. C Oury, E Toth-Zsamboki, J Vermylen, M F Hoylaerts. The platelet ATP and ADP receptors. Curr Pharm Des. 2006;12(7):859-75.